The invention is directed to a frequency converting device, i.e. a mixer for RF signals at receiver or the like, of the type employing signal and oscillator input means, a diode as a non-linear element and an intermediate frequency output, in which blocking circuits are provided in the vicinity of the diode for oscillations of the second harmonic of the oscillator frequency as well as the summation frequency of the oscillator frequency and the signal frequency.
An arrangement of this type is, for example, illustrated in U.S. Pat. No. 3,659,206. In such an arrangement, the currents of the undesired oscillations are isolated from the rest of the circuit by a blocking circuit on both sides of the diode.
The invention is directed to the problem of producing a frequency converting device, of the type referred to, which exhibits as small as possible a reflection factor at the signal and carrier input means, and where a termination reflector is involved has as low a noise figure as possible.